The ultimate goal of the Exposure Biology Program is to understand the development and progression of complex disease by precisely, accurately, and quantitatively assessing the individual's exposure to environmental stressors and the individual's responses to these stressors. Two of the most important risk factors for human morbidity and mortality are exposure to cigarette smoke and obesity, both assocaiated with systemic chronic inflammation and oxidative stress. The organizing theme the Center is that identification and validation of persistent modified proteins in plasma will provide specific information about the stressor, its mode of action, and the target organ. The environmental stress of the human and animal projects is focused on main-stream and side-stream cigarette smoke with obesity as a confounding physiological factor. We propose an integrated, multidisciplinary center with three research projects (human, mouse, and sensor) and two technology cores (proteomics and ELISA Microarray) which collectively will have four goals. Aim 1. Discover reactive nitrogen and reactive oxygen species (RNS/ROS) modified peptides using MS/MS as candidate biomarkers. Aim 2. Verification of RNS/ROS modified peptides as specific biosignatures using data-directed MS. Aim 3. Validation of RNS/ROS modified proteins for use as specific biomarkers for environmental stressors using custom-designed sandwich ELISA microarrays. Aim 4. Develop, test, and deploy two detector systems for exposure and for both specific and general markers of RNS/ROS response. A laboratory-based ELISA Microarray platform will be used to provide high-throughput, multiplexed analysis of dozens of analytes. The validated biomarkers will be also be deployed on a prototype, clinic-deployable detector system for on-site analysis. The sensor system is nanoparticle-based multiplexed Immunochromatographic / Electrochemical Biosensor (IEB) that will support the measurement of markers for exposure (cotinine) and response, both specific (modified proteins) and generic markers of oxidative stress and chronic inflammation, such as TNF-alpha, in a single platform. Critical Outcomes and Deliverables. The PNNL U54 Center will apply state-of-the-art proteomic and sensor technologies to provide NIEHS with a database of mode-of-action informing biomarkers of response, reagents for selected markers tested and validated in humans and informed by parallel studies in mice, and deployed on (a) a laboratory based ELISA Microarray platform, and (b) on a robust, clinic-deployable nanoparticle-based sensor suitable for use in large-scale human biomonitoring studies to evaluate the interaction of genes and the environment. The results of this U54 Center also will improve the scientific community's ability to compare, contrast and extrapolate biomarkers between humans and mice.